I got my high torque starter from Summit (SUM-G1665) and the nose seems too big to fit in the original 621 bellhousing. I measured the nose on the old starter and it is 2 1/2" but the nose on the new one is 3" at the widest point. The nose at the bottom of the new starter hits the bellhousing and forces the starter up against the block and there is no way it will go in there. Called Summit and their only suggestion was to sell me a mini starter for $230 or try grinding off some of the nose on the one I've got. Not thrilled about the second idea. Are those my alternatives?

Check out my other post in Chevelle Tech if you need a laugh! (Socket in header tube!) I've got the luck.

Scott,
I can almost bet that I know what the problem is without even seeing the starter.
Is the nose of the Summit starter aluminum? If so, that is the problem, plain and simple. A 621 housing MUST use a starter with a cast iron nose. The alum nose will only work with an auto tranny.
Now, there may be relief nearby. Does your old starter have a cast iron nose? If so, you can swap the noses (or maybe you have a good starter/alternator shop nearby that would do it). ;)

Tom,
Yes, the old one is sitting there in the garage and yes, the new one has an aluminum nose. How hard a task is it to switch them? I'm not at home to really look them over. Thanks for the shimmer of hope!

Scott,
It really is quite simple to change the noses.
1. Remove the solenoid on top of the starter.
2. Remove the 2 loooooooooooong bolts which run the length of the starter housing.
3. Carefully pull the nose away from the main case (be careful that you don't pull the armature out).
4. There is an engagement fork which goes over the starter drive that will need to be manuvered off of the starter drive.
5. Assemble in reverse order.

When starters are NEW, they are built with a stud on the end of one of the long bolts. This bolt is the UPPER bolt for attachment to the starter brace that attaches to the side of the block. If the Summit starter doesn't have the long bolt with a stud, and the other starter does, then swap the bolts and use a starter brace!

I am so sorry that you did not know in advance that a manual tranny bell housing (this ONLY applies to the bell housing for the BIG flywheel) MUST use a starter with an iron nose. When you get home, compare the 2 noses, and you will IMMEDIATELY see the difference!!!!
This is just one of those little things which you have to know about. There is NOTHING which readily alerts a person to this little detail-----------------------but for sure, you'll never forget it in the future! Right?

After you're all done, CALL SUMMIT, ask to talk to a boss, and have a visitation with him about this. THIS IS ONE OF THE LITTLE THINGS THAT THESE PEOPLE SHOULD KNOW ABOUT--------------------obviously you see how much grief it can cause!!!!